Confidentiality using symmetric encryption.pptx
- 3. Confidentiality using Symmetric Encryption • Traditionally symmetric encryption is used to provide message confidentiality. • Consider a typical scenario •Workstations on LANs access other workstations & servers on LAN •LANs are interconnected using switches/routers •With external lines or radio/satellite links
- 5. Confidentiality using Symmetric Encryption •Consider attacks and placement in this scenario •Snooping from another workstation •Use dial-in to LAN or a server to snoop •Use external router link to enter & snoop •Monitor and/or modify traffic on external links
- 6. Confidentiality using Symmetric Encryption •Have two major placement alternatives •Link Encryption •End-to-End Encryption
- 7. Location of Encryption Device Link Encryption • Encryption devices are placed at each end of the link • Encryption occurs independently on every link • All the communication is made secure • A lot of encryption devices are required
- 8. Link Encryption Implications •All paths must use link encryption •Each pair of node must share a unique key •Large number of keys should be provided
- 9. End-to-End Encryption • Source encrypts and the Receiver decrypts • Payload encrypted • Header in the clear • Only destination and reciever share the key • High Security: Booth link and end-to-end encryptions are needed.
- 10. Encryption Across a Packet Switching Network
- 11. Traffic Analysis • When using end-to-end encryption must leave headers in clear • So network can correctly route information • Although content is protected, traffic flow patterns are not • Ideally want both at once • End-to-End protects data contents over entire path and provides authentication • Link protects traffic flows from monitoring
- 12. Placement of Encryption • Can place encryption function at various layers in OSI Reference Model • Link encryption occurs at layers 1 or 2 • End-to-End can occur at layers 3, 4, 6, 7 • As move higher, less information is encrypted but it is more secure and more complex with entitled and keys
- 13. Encryption coverage implications of store and forward communications
- 14. Traffic Analysis • Monitoring of communications flows between parties • Useful both in military & commercial spheres • Link encryption obscures header details • But overall traffic volumes in networks and at endpoints is still visible • Traffic padding can further obscure flows • But at cost of continuous traffic
- 15. • Presented by: Ayush Jain • Enrolment number: IU1941090004
- 16. Thank You.